【図面の簡単な説明】[Brief explanation of the drawing]
第１図乃至第２図は内部受光式一眼レフレツク
スカメラに於てレンズ交換により測光指示誤差が
生じる原理を説明する図で、第１図は露出計機構
の受光部をフイルム面に置いた場合での上記原理
説明図、第２図は露出計機構の受光部の実際の光
量の関係から上記原理を説明する図、第３図は本
発明装置の実施例を示す要部の分解斜面図であ
る。
Figures 1 and 2 are diagrams explaining the principle of light metering error caused by lens replacement in an internal light-receiving single-lens reflex camera. FIG. 2 is a diagram explaining the above principle from the relationship of the actual light amount of the light receiving part of the exposure meter mechanism, and FIG. 3 is an exploded perspective view of the main parts showing an embodiment of the device of the present invention. It is.
【発明の詳細な説明】[Detailed description of the invention]
被写界の明るさを検出する受光素子を撮影光路
中或いはフアインダーピントグラスの後方に配置
した内部受光式測光方式（TTL方式）をもつて
絞開放下での露出決定を行うようなレンズ交換可
能の一眼レフレツクスカメラでは、撮影レンズを
通過しフイルム面に達する被写界光を実測すると
は云え、特に上記実測効果を発揮させる為に受光
素子をフイルム面に設けたような場合でも、この
まゝでは露光条件をきめる絶対的な露出計測の方
法とは云えず測光指示の正確を期す為には各交換
レンズの最大口径比が夫夫異なることに対処して
補正しなければならないことは勿論であるが、そ
の他にその指示動作には幾分の補正を必要とす
る。
何故ならば、使用する撮影レンズにはそれ等個
有のレンズ系、レンズ素材の光吸収率、反射率及
び鏡筒の乱反射の程度、斜入光の影響等が夫夫異
なり、且レンズ機種個有の射出瞳の位置及び該瞳
面の大きさ、ビネツテイングによるケラレの度合
が異なる等各レンズの光学的条件の違いからし
て、これ等レンズを交換して使用する場合に上記
測光方式では、フイルム面の明るさが各交換レン
ズの同じＦNOに対して相違するからである。
一方、カメラ本体に組み込まれた受光素子の位
置によつても、その位置個有の測光特性があるか
ら、これを考慮して補正する必要が有る。
この事を第１及び第２原理図を参照して更に詳
細に説明するに、理解を容易にする為に以下の説
明では無限遠にある輝度一様な被写界を対象とす
ることを前提とする。そして、フイルム面に受光
素子を置いた場合のＴNO対電流の関係を示す第１
図に於て、太線ＬS及びＬAはＦNO目盛に対する電
流実測値で、ＬSは交換レンズ中基準となるレン
ズの特性を示し、ＬAはある交換レンズの特性を
示す。細線はレンズ系に無関係な明るさに対する
電流特性を示す。ここで、太線ＬS及びＬAの図上
左方上部が直線的でないのは、上記レンズのビネ
ツテイングの影響等が絞開放附近で大きく影響す
るからであり、これ等太線ＬS及びＬAが略平行的
に位置するのは、各レンズの上記諸因子から成る
光学的条件の相違によりこれ等レンズを通過する
実効光量の相違に起因する。そして横軸ＦNO目盛
の第二段目は太線ＬSの各ＦNOに於ける電流値を
横軸に平行に移動して細線と交つた点を縦軸に平
行に第二段目の目盛線まで下し、その交点に各Ｆ
NO目盛を付し、これをＬSVとしたものである。ま
た横軸ＦNO目盛の第三段目は上記ＬSVと同じ要領
により太線ＬAについてＬSと同様にひき写された
ＬAVを表示したものである。
この様にして得たこの図から判ることは交換レ
ンズは同じＦ値を有していても、それぞれ使用す
るレンズによるフイルム面照度が異ることが明ら
かとなる。今その差をβと呼び単位をEVとす
る。
第２図の太線ＬCは実際の露出計測光受光部に
おける光量（単位はEVとす）と電流の関係を示
す。太線ＬC上の点Ｓは基準レンズの開放に於け
る電流値を示し、点Ａは交換レンズの開放に於け
る電流値を示したものである。点Ｓと点Ａとの横
軸上の差は基準レンズとある交換レンズの開放に
於けるEV差を示したものである。そのEV差をα
と呼び単位をEVとする。
しかして絞以外の露光要素を一定とした時、基
準レンズではＬSVに於て適性露光が得られるよう
に絞機構と連動する作用部材と露出計機構の光−
電流変換回路中に設けた抵抗体とを関係づければ
よいが、ある交換レンズを使用の場合、もし仮り
にその絞作用部材をＬSVと同じ位置に設けると前
記第１図第２図に示したα、βにより基準レンズ
に対して露出誤差を生じる結果となる。したがつ
て同じＦ値に対してある交換レンズの測光指示Ｌ
SVの測光指示とあたかも同一測光指示にするため
に交換レンズの絞作用部材をαだけ補正を行う必
要がある。しかしこの段階までの補正では第１図
にて説明されたＴNO補正のβは加味されていな
い。
従つて、上記レンズの光学的諸因子の相違に起
因する内部受光露出計機構に於ける測光指示誤差
を補正するには、上記抵抗体を用いた補正手段を
構じた場合にこの抵抗体の抵抗値を規制する絞作
用部材を上記α及びβに応じて定める必要があ
る。そこで絞作用部材の位置をαとβに応じて定
めることにより基準レンズに対して交換レンズは
各絞り位置で同一露光を得ることが出来る。以上
の補正要領によれば露出計測光受光器の位置をフ
イルム面上に設けた場合或いはフイルム面上以外
の撮影レンズ背後任意の位置に設けた場合でも同
様に補正し得て正しい露光を得ることが出来る。
而して本発明は、上記補正要因及びこれに対処
する補正要領によつて、適切な補正結果を与えよ
うとするものである。この為に内部受光式測光方
式レンズ交換可能な一眼レフレツクスカメラに於
て、絞開放下での測光に際して調定される絞値条
件を測光指示動作に変位量として附加する作用部
材を各交換レンズに夫々設け、該作用部材を絞値
調定部材に連繋して変位駆動させるに当り、その
変位起点を基準となる撮影レンズに対する各交換
レンズのフイルム面照度並びに絞開放下での露出
計受光部に於ける基準レンズと交換レンズとの
EV差に応じて調定し、各交換レンズごとの測光
指示動作が適正露光となるようにしたものであ
る。
以下図示の実例により本発明の要旨とするとこ
ろを詳述すると、１は交換レンズ鏡筒、２は絞値
調定環で、これには絞作用部材３が一体に取り付
けてある。そして該絞調定環２は絞連動下にその
等間隔なる回動角をもつてフイルム面照度が倍数
的に変化するように、例えば第１図示の太線ＬS
の特性を有するフイルムでは第二段横軸ＬSVに配
したＦNO目盛に従う如きそのレンズ特性に対応し
た回動角をもつてフイルム面照度がEV値で直線
的に変化するように構成してあり、且絞作用部材
３は前記絞調定環２が回動起点に在る時基準とな
る撮影レンズに対するこの交換レンズのフイルム
面照度並びに該基準レンズとこの交換レンズとの
絞開放下でのEV差に応じて、後述する可変抵抗
器４の抵抗体５に対する位置が調定してある。そ
して上記可変抵抗器４はカメラ本体内に配設さ
れ、交換レンズをカメラ本体に装着した際その摺
動子６が前記絞作用部材３に規制されて、該作用
部材３と抵抗体５との関係位置に外じて抵抗値を
可変するようになしてあり、電源電池７、受光部
８、指示計器９を直列に接続した露出計器構の回
路中に挿入してある。そして受光部８はCdS素子
８′及び８″更に抵抗８等から成り、受光面照度
の倍数的変化に対してその光導電電流が等差級数
的に変化するように調整してある。又指示計器９
は互に反作用性向上を有するコイル９′及び９″を
備えた差動型電流計からなり、該コイル９′には
前記受光部８で規制される電流が与えられ、他方
のコイル９″には前記可変抵抗器４及びこれに並
列に接続されフイルム感光度又はシヤツター速度
或いはこれ等の相関々係値に応じて調定される可
変抵抗器１０により規制される電流が与えられる
ように構成してある。又、これ等可変抵抗器１０
はシヤツター露出時間の倍数的変化等に対して等
差級数的な出力電流を得る如き変化特性を有し、
殊に可変抵抗器４はその摺動子６の回動変位角に
対しその規制電流値が等差級数的に変化するよう
になしてある。
以上のような構成であるから、この本発明装置
の実例では、露出計機構の回路動作が各回路部材
の等差級数的な電流変化に対処する特性によつて
受光部８による被写界条件に対して絞調定環２に
よる絞値条件附加が広範囲の条件に対して常に適
確に行われる状態にある。而して今仮りに第１図
上太線ＬAで示されるような特性を有す交換レン
ズを使用した場合、この交換レンズがもたらす前
記フイルム面の照度及び受光部８のEV差等の補
正要因に応じて変位起点を調定された絞作用部材
３が摺動子６に作用してこれを抵抗体５に対して
変位させるから、可変抵抗器４はその抵抗値を変
えて受光素子８が規制する指示計器９の作動に対
する差動々作量を変えるように作用する。従つて
該計器９は上記補正要因をその指示動作に附加さ
れる。
而して本発明装置によれば、上記特定の交換レ
ンズを用いた場合の補正のみならず、各種交換レ
ンズにそれ相応の補正要因に応じて各絞作用部材
の変位起点を決めれば、種々の交換レンズに適用
して良く測光指示動作の補正をなし得ることは勿
論である。
斯かる如く、本発明装置は内部受光式測光方式
に於て、受光部を如何様な場所に配置した場合で
も生じる指示誤差をレンズ交換した際にも良く補
正することが出来て、各種レンズに相応して常に
正確な測光が出来る。
尚上記本発明装置を説明するに、露出計機構の
測光指示値補正手段として可変抵抗器を用いた電
気的な手段をもつて行つたが、これに替えて機械
的手段例えば指示計器自体又は指標部等を補正量
に応じて変位駆動するような連繋機構の構成をも
つてしても良く、又、指示計器を用いず純電気的
動作によつて露光量を調定するような機構に対し
ては、本発明の要旨とするところに従い該機構の
作動回路中の可変抵抗器或いはコンデンサー等の
その他の回路素子を可変又は切換る等なすことに
よつて所期の補正を行うことが出来る。
It has an internal light-receiving metering system (TTL system) in which a light-receiving element that detects the brightness of the subject is placed in the shooting optical path or behind the viewfinder focusing glass, making it possible to change the lens to determine exposure even when the aperture is wide open. Although single-lens reflex cameras actually measure the field light that passes through the photographic lens and reaches the film surface, this measurement is difficult even when a light-receiving element is provided on the film surface to achieve the above measurement effect. However, it cannot be said that there is an absolute exposure measurement method that determines the exposure conditions, and in order to ensure the accuracy of photometry instructions, it is necessary to compensate for the fact that the maximum aperture ratio of each interchangeable lens is different. Of course, the instruction operation also requires some correction. This is because each photographic lens used has its own unique lens system, the light absorption rate and reflectance of the lens material, the degree of diffuse reflection of the lens barrel, the influence of oblique light, etc., and each lens model is different. Due to the differences in the optical conditions of each lens, such as the position of the exit pupil, the size of the pupil plane, and the degree of vignetting due to vignetting, the photometry method described above requires that when these lenses are used interchangeably, This is because the brightness of the film surface is different for each interchangeable lens with the same F NO . On the other hand, the position of the light-receiving element incorporated in the camera body also has its own photometric characteristics, so it is necessary to take this into account when making corrections. This will be explained in more detail with reference to the first and second principle diagrams.In order to make it easier to understand, the following explanation assumes that the object is a field with uniform brightness at infinity. shall be. The first graph shows the relationship between T NO and current when the photodetector is placed on the film surface.
In the figure, thick lines L S and LA are actual measured current values with respect to the F NO scale, L S indicates the characteristics of a reference lens among interchangeable lenses, and L A indicates the characteristics of a certain interchangeable lens. The thin line shows the current characteristics with respect to brightness, which is unrelated to the lens system. Here, the reason why the upper left part of the thick lines L S and L A in the figure is not straight is because the influence of the vignetting of the lens mentioned above has a large effect near the open aperture, and these thick lines L S and L A are The reason why they are located substantially parallel is due to the difference in the effective amount of light passing through each lens due to the difference in the optical conditions of each lens consisting of the above-mentioned factors. The second stage of the horizontal axis F NO scale is the current value at each F NO of the thick line L S , which is moved parallel to the horizontal axis, and the second stage scale is set parallel to the vertical axis at the point where it intersects with the thin line. down to the line, and place each F at the intersection.
A NO scale is attached and this is called LSV . Further, the third row of the horizontal axis F NO scale shows L AV which is drawn from the thick line LA in the same way as L S in the same manner as L SV above. As can be seen from this diagram obtained in this way, even if the interchangeable lenses have the same F value, the illumination intensity on the film surface differs depending on the lens used. We will call the difference β and its unit will be EV. The thick line L C in FIG. 2 shows the relationship between the amount of light (unit: EV) and current in the actual exposure measurement light receiving section. Point S on the thick line L C indicates the current value when the reference lens is open, and point A indicates the current value when the interchangeable lens is open. The difference between point S and point A on the horizontal axis indicates the EV difference between the standard lens and a certain interchangeable lens at maximum aperture. The EV difference is α
The unit is EV. Therefore, when the exposure elements other than the diaphragm are constant, the light from the operating member interlocking with the diaphragm mechanism and the exposure meter mechanism so that an appropriate exposure can be obtained at LSV with the reference lens.
It is sufficient to relate it to the resistor provided in the current conversion circuit, but when using a certain interchangeable lens, if the diaphragm member is installed at the same position as LSV , the result will be as shown in Fig. 1 and Fig. 2 above. The α and β shown result in an exposure error with respect to the reference lens. Therefore, the photometry instruction L of a certain interchangeable lens for the same F value
In order to make the photometry instruction the same as the photometry instruction of the SV , it is necessary to correct the aperture member of the interchangeable lens by α. However, in the correction up to this stage, β of the T NO correction explained in FIG. 1 is not taken into consideration. Therefore, in order to correct the photometry indication error in the internal light-receiving exposure meter mechanism due to differences in the optical factors of the lenses, when a correction means using the above-mentioned resistor is provided, it is necessary to It is necessary to determine the throttling member that regulates the resistance value according to the above α and β. Therefore, by determining the position of the aperture member according to α and β, the interchangeable lens can obtain the same exposure at each aperture position with respect to the reference lens. According to the above correction procedure, even if the exposure measuring light receiver is placed on the film surface or in any position behind the photographic lens other than on the film surface, the correction can be made in the same way and correct exposure can be obtained. I can do it. Therefore, the present invention aims to provide an appropriate correction result by using the above-mentioned correction factors and correction procedures corresponding thereto. For this purpose, in a single-lens reflex camera with an internal light-receiving metering system that has interchangeable lenses, the operating member that adds the aperture condition that is adjusted during photometry with the aperture open as a displacement amount to the photometry instruction operation is replaced each time. When the actuating member is connected to the aperture value adjusting member to drive the displacement of each lens, the illuminance of the film surface of each interchangeable lens with respect to the photographing lens and the exposure meter light reception when the aperture is open are determined using the displacement starting point as a reference. The difference between the reference lens and the replacement lens in the section
Adjustment is made according to the EV difference, so that the photometry instruction operation for each interchangeable lens provides the appropriate exposure. The gist of the present invention will be explained in detail below with reference to illustrated examples. Reference numeral 1 denotes an interchangeable lens barrel, 2 an aperture adjustment ring, and an aperture member 3 is integrally attached to this. The diaphragm adjustment ring 2 is rotated in conjunction with the diaphragm so that the illuminance on the film surface changes in multiples with rotation angles at equal intervals.For example, the thick line L S shown in the first figure
In the case of a film having the characteristics shown in FIG . When the aperture adjustment ring 2 is at the rotation starting point, the aperture action member 3 controls the film surface illuminance of this interchangeable lens with respect to the reference photographing lens and the aperture of the reference lens and this interchangeable lens when the aperture is opened. The position of a variable resistor 4 relative to a resistor 5, which will be described later, is adjusted according to the EV difference. The variable resistor 4 is disposed inside the camera body, and when the interchangeable lens is attached to the camera body, its slider 6 is regulated by the aperture member 3, and the contact between the action member 3 and the resistor 5 is controlled by the aperture member 3. It is arranged so that the resistance value can be varied by removing it from the relevant position, and it is inserted into a circuit of an exposure meter structure in which a power source battery 7, a light receiving section 8, and an indicator meter 9 are connected in series. The light receiving section 8 consists of CdS elements 8' and 8'', a resistor 8, etc., and is adjusted so that the photoconductive current changes in an arithmetic series with respect to multiple changes in the light receiving surface illuminance. Instrument 9
consists of a differential ammeter equipped with coils 9' and 9'' which have mutually improved reaction properties; a current regulated by the light receiving section 8 is applied to the coil 9', and a current regulated by the light receiving section 8 is applied to the other coil 9''. is configured to provide a current regulated by the variable resistor 4 and a variable resistor 10 connected in parallel thereto and adjusted according to the film sensitivity, shutter speed, or the correlation value thereof. There is. Also, these variable resistors 10
has a change characteristic such that an output current is obtained in an arithmetical series with respect to a multiple change in shutter exposure time, etc.
In particular, the variable resistor 4 is configured such that its regulated current value changes in an arithmetic series with the rotational displacement angle of the slider 6. Since the configuration is as described above, in this example of the device of the present invention, the circuit operation of the exposure meter mechanism is adapted to the field conditions by the light receiving section 8 due to the characteristic of coping with the arithmetical current changes of each circuit member. However, the addition of the aperture value condition by the aperture adjustment ring 2 is always performed accurately under a wide range of conditions. Therefore, if an interchangeable lens having the characteristics as shown by the thick line L A in FIG. The aperture member 3 whose displacement starting point is adjusted according to It acts to change the differential actuation amount for the operation of the indicating instrument 9 to be regulated. Accordingly, the meter 9 has the above-mentioned correction factor added to its indicating operation. According to the device of the present invention, not only correction can be made when using the specific interchangeable lens described above, but also various corrections can be made by determining the displacement starting point of each diaphragm member according to the correction factor corresponding to each type of interchangeable lens. Of course, the present invention can also be applied to interchangeable lenses to correct the photometry instruction operation. As described above, the device of the present invention is capable of well correcting the indication error that occurs when the light receiving section is placed in any location in the internal light receiving type photometry method, even when changing lenses, and is suitable for various lenses. Correspondingly, accurate photometry is always possible. In the above description of the device of the present invention, an electrical means using a variable resistor was used as the photometric indication value correction means of the exposure meter mechanism, but instead of this, mechanical means such as the indicator itself or an indicator may be used. It is also possible to have a structure of a linking mechanism that displaces and drives parts etc. according to the amount of correction, and also for a mechanism that adjusts the exposure amount by pure electrical operation without using an indicator. In this case, the desired correction can be made by varying or switching other circuit elements such as a variable resistor or a capacitor in the operating circuit of the mechanism according to the gist of the present invention.
【特許請求の範囲】[Claims]
１ 内部受光式開放測光方式レンズ交換可能な一
眼レフレツクスカメラに於て、測光に際してプリ
セツト調定される絞調定環を等間隔回動角をもつ
てフイルム面照度が倍数的に変化するように構成
し該環に測光指示動作に係合する作用部材を設
け、その作用部材の位置を開放に於ける基準レン
ズに対する各交換レンズのフイルム面照度並びに
受光部に於ける照度差に応じて調定し各交換レン
ズ毎の測光指示動作が適正露光となるようになし
たことを特徴とするレンズ交換可能な一眼レフレ
ツクスカメラに於ける絞と露出計との連動装置。
1.In a single-lens reflex camera with internal light receiving and open metering system with interchangeable lenses, the aperture adjustment ring, which is preset adjusted during photometry, is rotated at equal intervals so that the illuminance on the film surface changes in multiples. The ring is provided with a working member that engages with the photometry instruction operation, and the position of the working member is adjusted according to the film surface illuminance of each interchangeable lens with respect to the reference lens in the aperture state and the illuminance difference at the light receiving section. 1. A device for interlocking an aperture and a light meter in a single-lens reflex camera with interchangeable lenses, characterized in that the light metering instruction operation for each interchangeable lens is set to a proper exposure.